Fiberglass!

I just got the resin, primer and some sheets of glassfiber in the mail. Soon, I will be making many excellent things.

But before I do, how should I prep the areas I'm going to glass? Will glass stick to metal or do I need to make something that embeds into the glass? Any tips for how to lay glass efficiently so that it stays strong? Any tips for cutting it once I've got my shape?

There are professional agents that keep the resin from sticking tot he mold/pattern. The main ingredient is Poly Vinyl Alcohol (PVA). These can get pricey. a cheap alternative is carnuba wax.

The resin will stick to metal. it has a much harder time sticking to plastics. To get a lot of strength, alternate layers of mat and cloth, and lay the weave in 45 degree alternating layers. Use only enough resin to wet the glass, to much can cause heat and gases to build up between layers. Allow each layer to set up for a half hour or so between them also to avoid bubbles between layers that can cause lamination flaws.

Cured composites can be cut with traditional mechanical tools like jigsaws, grinders, rotary tools, and shaped with sanders or the like. Respiration protection is advised.

4cylndrfury wrote: Cured composites can be cut with traditional mechanical tools like jigsaws, grinders, rotary tools, and shaped with sanders or the like. Respiration protection is advised.

I wouldn't say advised. Just wear respiration protection unless you want the next day to SUCK! Also I would recommend covering as much skin as possible.

DO NOT get it on your hootus

thin wafer disc on a die grinder will cut cured fiberglass like a hot knife through butter

We did something over at Classic Motorsports that might help: http://classicmotorsports.net/articles/glasswork/

Also, powerblock had some cool stuff on fiberglass too...

http://www.powerblocktv.com/two-minute-tech/2min-79/make-a-fiberglass-hood-part-1

http://www.powerblocktv.com/two-minute-tech/2min-80/make-a-fiberglass-hood-part-2

http://www.powerblocktv.com/two-minute-tech/2min-231/fiberglass-fabrication

Also, what specifically is your goal? Your point about glass "sticking" to metal is a bit vague...do you want it to stick? Do you want it to release? If you want it to stick, its actually likely a better idea to make the part, then mechanically fix it to the car (rivets, screws etc), then bondo the seam if possible. If you want it to release, then follow the tips listed/linked.

They also make a "film" that needs to be heated in an oven to bond fiberglass or carbon fiber to metal. We used it in college to bond carbon fiber to aluminum honeycomb.

As far as releasing from a mold, we used Stoner mold release with a fair amount of success.

I have a full set of body molds for my race car and have made a full set. The rule on molds is:

• New molds need 3 coats of wax minimum. I use Partall brand. Each coat is rubbed in w/ a soft cloth and buffed off w/ microfiber cloth.

• Well "seasoned" molds can get cleaned and one coat applied and removed as above.

• PVA - polyvinyl alcohol - can be sprayed on w/ a large tip on a spray gun, or applied with a wad of soft cloth. Again, I use Partall brand.

Also - for fiberglass supplies, these guys are great. Also, they're local to DC/Baltimore/Del/Philly

Fiberglasssite

From one of our own . . .

I'm mostly looking to glass over a patch I made for rust. That's why I was asking about bonding to metal. I had planned to use a wire wheel to get everything nice and clean and then just glass over the area.

Past that, I was going to make some vents for my front fenders. Maybe, eventually, I'll make a hood and trunk.

Thanks for all the help, guys. I'm getting some really cool ideas.

Polyester resin or epoxy? Hakes a very large difference.

foxtrapper wrote: Polyester resin or epoxy? Hakes a very large difference.

Epoxy.

I made this fiberglass copy (it's the shift porch for a '61 Pontiac, the thing that sits on the transmission hump and the floor shift lever sticks up through.) I covered the original part with clear plastic packing tape and it worked pretty well; after the fiberglass cured it popped off pretty easily.

edit: as for making fiberglass stick to metal, when patching a rust hole, I've had good results by simply cleaning up the area around the hole with a wire brush and 80 grit sandpaper until the metal is clean, shiny and has a 'tooth' that the glass resin can grab on to.

Don't mix more than a small drink cups worth of epoxy at a time. It kicks slower in smaller batches, giving you more work time.

Use the metered pumps to get the ratio of epoxy to activater right and consistent.

Use the right activator for the weather conditions.

Get to know the various fillers for the epoxy. Very usefull stuff those fillers. Use a squeegee and roller to work the epoxy into the glass. Use as much glass as you can. Do not make the balance epoxy heavy, it will be weak and brittle if you do.

Epoxy will stick to clean metal, but it's a mechanical bond. The rougher the surface, the better the bond. 20 grit paper works well.

Plastic requires a rougher surface. I'll jag a cheese grater file into it creating a ridiculous surface for mechanical bonding.

Throw away every cup, mixer stick, etc as you use it. False economy to try to save and reuse them.

Beware the fumes! Work outside and well ventilated. Everyone eventually becomes allergic to the isocyante fumes. When you finally do, you will never be able to work with the stuff again. Period. So do what you can to delay that time as long as possible.

Okay, I just built my first template out of packing take and a plastic bottle. My priorities for the first session are -

1. Cover repaired rust hole.
2. Built the fender vents.
3. Build a mold off the hood.

We'll see if I have enough material to do all three, but so far I think this will be ...

VERY NICE!